nutmeg1828

I need some help. I have a 1990 Camaro RS V6 (automatic) and it continuously shuts off at stop lights. I've gotten everything done that I can think of and am very tired of putting more and more money into things that aren't fixing the problem. When I'm sitting at stop lights or stop signs my car occasionally just dies. I can usually tell when its going to happen so i hold my brake and press the gas to keep it running. Other times, my car will idle really low ( I can't give RPM's because my guage is way off) but i can hear it and then all of the sudden something will happen and my car will rev up really high and want to jet (i've almost rearended quite a few people because of this). I have an older brother who works on camaros/trans ams and such and he has told me everything he thought was possibly wrong and when nothing worked i took it to a garage and had them hook it up to a computer to see what they could find. So far everything i have fixed has not worked.

New fixes are:
1. new air filter
2. new fuel filter
3. new oil filter
4. air intake cleaned
5. throttle body cleaned
6. all new spark plugs and wires
7. new, but used transmission (this came from a different problem but didnt help the current one....the shutting off problem was happening before the new tranny)


The only thing i haven't tried fixing that i have been told might be a problem is the map sensor and the O2 sensor, but i would have thought when the garage hooked it up to the computer they would have been able to tell me if those two things were bad.

If any one has any idea how i can possibly fix my car, please let me know. I am up for new ideas...

Thanks, Jess

xplane

well the dying at stop lights sounds like a major vac leak but the lagging then taking off is something i had but never figured out, I replaced the ECU and it went away.

2_point8_boy

I know you listed cleaning the TB, but did you also clean out the IAC passages? How did the IAC itself look? You might want to replace it on general principle if it's never been replaced to your knowledge. They are veryprone to becoming lazy and not being able to set the correct idle.

There are a few things that are responsible for giving you a good idle: TPS, IAC and MAP/MAF sensor, and minimum air rate.

There's a common misconception amoung board members and the general public(mainly people who don't know much about Fuel Injected cars) that pluggin into the computer and reading data is going to tell you what to fix. The fact is that on our cars, the live data is fairly useless, newer cars it's better, but there is no such machine that will tell you exactly what needs to be replaced. I personally never use live data on an OBD-I car to diagnose problems unless I absolutly have to. Not saying not to use it ever, I'm just saying to be careful about thinking that it's going to be that easy.It just points you in the right direction if your lucky, it's your job to interpret it right.

My advise to you: Take your time, break out the Digital Volt/Ohm meter, and check sensor VOLTAGES, not ohm readings.

checking actuators are going to be the tough one for you since you really do need specialized equipment to do it. Check out the sensors I mentioned, I can get the specs at idle for you on all the voltages if you need them(IAC is an actuator, not a sensor, so you'll just have to make sure all the sensor signals are good, then deduce that the IAC is toast).

Good Luck

bobdole369

Nope ECM on these cars will usually only tell you if a sensor is giving out of range readings. You can have a totally bad sensor that is giving within range readings hence no codes. MAP sensor causes lots of problems when it goes.

Heres a question.... Does the stalling happen when the car is very cold? (i.e. first thing in the morning in the first 3 minutes of driving it?) The ECM ignores the O2 sensor until it heats up, so you can rule it out that way.

6. all new spark plugs and wires

I know you have new plugs and wires, but I wonder if your actually firing on all 6? The car will run just fine with a totally dead cylinder. I know because I inadvertantly melted number 4 plug wire to the header not too long after I got my 89 bird. I ran it for 3 months just like that wondering the whole time why my car was idling so freakin weird and stalling at lights.

Maybe you might want to pull a plug at a time, ground the plug on the engine, and crank the motor. Your looking for a bright blue spark. Your plugs ought to be light greyish/brown with no deposits other than a nice thin ash.

Have you tried pulling your own codes? (search is your friend here.)

Idling problems are very often vacuum leaks. The OEM vacuum lines turn very brittle after 15 years, often best to replace all of them just to be sure. Hairline cracks are very hard to actually see.

IAC is often another cause of stalling and surging. As above, the IAC passages aren't usually cleaned if you had this work done at a shop. TPS is almost critical for idle, in fact my car will NOT stay running without the TPS plugged in.

Is your EGR valve holding vacuum? Often the diaphraghm cracks and you have a pretty good sized invisible vacuum leak.

Hope any of this helps.

nutmeg1828

I never run my car when its very cold, i usually park it in october and dont bring it back out till late april early may. as far as the plugs go, i used to be running on only 4, but when i replaced them all im running on all 6 now. thats the first thing i fixed because thats what everyone was telling me was the cheapest/possible fix. as for the vaccum leaks, im not quite sure what those are (im not car smart...) but i do know that my brother said i have some type of leak some where becuase occasionally my exahaust smells very much like sulfer and he can see something leaking out exahaust under the hood near the firewall in the back.... i thought he told me it was an exhaust leak, but maybe its the vaccums he was talking about. as for the iac, i didnt realize it, but i talked to my brother about the suggestions you guys had made and he told me we did replace that already. so i guess thats already been done. also, he told me we did replace the O2 sensor, i didnt think we did.... he does the work on my car, i just buy the parts....he remembers the things that were a pain in the ***... i dont.

as for the rest of the things that were mentioned i'll work on replacing them one by one till i get the correct thing. thanks for all the help

2_point8_boy

That can get really expensive if the problem actually lies in the wiring somewhere. Not trying to be negative or aggrevating, but if your brother isn't checking the actual signals, powers and ground, and he's just telling you to buy parts until something works, he's not that great of a mechanic. Sometimes you can replace every single sensor and actuator, and even the computer, but if you have a bad wire , none of it matters, you know.

Firebreed

check all the rubber lines (the black lines running to and from the engine) and replace them if they looked cracked, chances are, they need to be replaced anyways so replace them, I had that problem myself, replacing all the rubberlines (i have yet to do the hard plastic lines) made my car stop dieing at the redlights/stopsigns, though i do have a rough idle that i still havent been able to correct (also, i had my cat converter replaced, the thing was orginal and CLOGED so badly it caused my car to run very very poor, horble idle, ect ect.)

I still have a bit of a rough idle, and i cant seem to get the idle to stay set during between open and closed loop (carbed car got to mess with it more :sigh

jstrdn90rs

I own basically the same car with the same symptoms you described.My car died at every light just about...until I replaced my brake booster and then it was 95% fixed ...only did it once in awhile.I then replaced my pick-coil and ignition module on the distributor and it hasnt died once..not even come close.But make sure you have no vacuum leaks as others descibed..a bad brake booster is a huge vacuum leak when you press on it.You can test it by letting the car idle and pressing the pedal and watching the idle/rpms if they become unstable ,then you have a leaky booster.The idle shouldnt change when you press the pedal.

nutmeg1828

my brother isnt a mechanic....he works on cars for fun.. but i understand where you comming from when you say if i replace everything in parts it could still be happening....ive already spent about $300 tryin to fix it. im going to try the vaccum lines because a lot of the replies mention vaccum and i checked into that and its not too expensive. as for the brake booster, ill prolly hold off till way later to attempt that one becuase my car only does it once in awhile. it has its good days and its bad days...more good than bad though.

jstrdn90rs

My car has 129,000 on it and I just yanked the distributor and installed a new pick-up coil its like 10-15 bucks..you have to disassemble the distributor to get it off , its not hard either.While I was there I replaced the ignition module which is a little more like 40-50 bucks.Some people like the aftermarket stuff,but speaking from experience..I installed a Wells brand module and started having problems..I pulled the module and the cooling grease(di-lectric grease) was gone..I mean it was burned off the distributor base..Car wouldnt start when warm...so I purchsed an AC DELCO and havent had a problem.I dont think these modules are compatable ..not sure on the Accel or high per ones ,but the standard ones are junk.I think you will find your problem there..hardest part is pulling the distributor and resetting it.

CharcoalBird

iTrader: (4)

I had the same problem for awhile, took me months of saving and changing parts, turns out I had 2 bad fuel injectors. Once you think you've changed everything...check your fuel injectors.

Things I changed that didn't help:
Vaccum Lines
Pick-Up Coil
Ing. Coil
Distributor
Plugs and Wires
EGR Valve
IAC
Fuel Filter
Air Filter
That's all I can think of for now.

nutmeg1828

alrighty, ill keep that in mind.

Firebreed

I would check the injecters first, just in case.

CharcoalBird

iTrader: (4)

Also, getting your fuel injectors cleaned may help. After I got mine cleaned the car didn't stall out, but it did idle irratically. They may just be clogged. That was one of the first things I did to try and fix the problem. What the place that cleaned them didn't tell me was that 2 of them were bad. I had to take it to my own mechanic for them to tell me that's what was wrong.

SouLTeRRoR

I have a similar problem and have replaced most of the things metioned above. I also replaced my MAF sensor and that fixed the problem a lot. I am having problems with some of my vac lines right now and I'm gonna check on that brake booster my self.

Stryder

hmmm sounds like egr to me

DustyJL

Try replacing the ignition module. Mine did the same thing and I replaced so much stuff and finally someone told me to change the igniton module. I changed it and it ran good after 6 months of dainoses.

Dany89

Hey man my car was doing kind fo the same thing, it stalled at stoplights or stalled over a while of dirving. My car is curretly in the shop and they toled me it was the distribuator and or the pick-up coil. give it a try man